Flapper Valve Research Articles

Experimental Assessment and Future Applications of the Shikani Tracheostomy Speaking Valve.

Tracheostomy speaking valve use may increase airflow resistance and work of breathing. It remains unclear which valve offers the best performance characteristics. We compared the performance characteristics of the Shikani speaking valve (SSV; unidirectional-flow ball valve) with those of the Passy-Muir valve (PMV; bias-closed flapper valve). Airflow resistance was measured for both the SSV and the PMV at 8 flow amplitudes and in 3 orientations (-15°, 0°, +20°) in the bias-open and bias-closed configurations. Significantly lower airflow resistance was observed for the SSV (bias open) compared with the PMV at -15° (p < .001), 0° (p < .001), and +20° (p = .006) from the horizon. No significant difference was observed between the PMV and the SSV (bias-closed) configuration at any of the tested angles. A nonsignificant trend toward decreased airflow resistance was observed between the SSV bias-open and bias-closed configurations at each of the angles tested. The SSV demonstrated lower airflow resistance compared with the PMV across 8 flow amplitudes in the bias-open configuration at -15°, 0°, and +20° from the horizon. Further investigation is needed to determine the clinical impact of these findings on patient comfort, work of breathing, phonation, and airway protection during swallowing.

Transient analyses of the Jordanian 5 MW research reactor under LOEP accident

The Jordanian 5MW research reactor is simulated to investigate its transient behavior under a Loss Of Electric Power (LOEP) accident. The reactor cooling system is under downward force convection during normal operation, and upward natural convection through flap valves during training and shutdown modes. A coupled neutron kinetics and thermal hydraulic model is used to analyze the behavior of the reactor under various conditions: (1) a wide range of open positions of flap valves, with valve opening pressures ranging from 0.5 to 3kPa, (2) three pump coastdown flow rates of 100%, 50%, and 25% of the nominal value, and (3) number of flap valves: one and two. As a reference, the evaluation of the reactor parameters in the hot and average assembly is performed when the pressure difference across the flap valves is reduced to 1.5kPa, as the design value. The flow inversion times in the hot and average assembly are analyzed for all of the cases. The second temperature peaks of coolant and fuel are presented in the analysis. This study discusses the differences among these cases. The general behavior of the reactor during LOEP is similar, but there are variations in important parameters such as flap valve open time, flow inversion time, and maximum fuel and coolant temperatures.

Servo Valve Nozzle Fuzzy Clustering Analysis Pairing Algorithm

Electro-hydraulic servo valve is the key component of an electro-hydraulic servo control system, and double nozzle flapper valve is the main type of electro-hydraulic servo valve. Nozzles are the important part of a double nozzle flapper valve, the pairing quality is directly related to the performance of the servo valve .Servo valve is of symmetrical structure, and the use of nozzles is also in pairs. The process of nozzles matched in pairs is called pairing process. Because the orifice diameter of the nozzle is only about 0.2 to 0.3 mm, it is difficult to pair with the method of direct measurements. Besides, as a kind of hydraulic components, nozzles are usually paired by flow rate measured under differential pressure. Two nozzles will be matched to a pair if their pressure-flow rate characteristic curve is within the allowed tolerance. To ensure the success rate of pairing, it usually needs a large number of machined nozzles to be sifted. According to the principle of clustering analysis, we propose a new paring algorithm which can match nozzles efficiently and automatically.

Development of a four-nozzle flapper servovalve driven by a giant magnetostrictive actuator

A novel configuration of a four-nozzle flapper servovalve driven by a giant magnetostrictive actuator is described, and giant magnetostrictive actuator displacement model and four-nozzle flapper valve pressure–flow equation are built, which can quantificationally describe the physical process from input current to control pressure in the giant magnetostrictive material–based four-nozzle flapper servovalve. Then, by a computational fluid dynamics method, control pressure under different zero-clearance configurations is determined by the numerical method and compared with the control pressure determined by a theoretical calculation method, which verifies the availability of the above-mentioned numerical method and the accuracy of the implemented numerical model. Subsequently, to elucidate the interaction rule between the control pressure and the orifice flow with the main structural parameters of a four-nozzle flapper servovalve, the parameters and the configurations of a single nozzle, four nozzles and a fixed orifice are investigated, which provides a theoretical basis for the design and optimisation of a giant magnetostrictive material–based four-nozzle flapper servovalve. A test system of a giant magnetostrictive material–based four-nozzle flapper servovalve is established, and the test results of static control pressure and hysteretic control pressure are obtained, which enables the determination of the maximum output control pressure.

An Innovative Passive Residual Heat Removal System of an Open-Pool Type Research Reactor with Pump Flywheel and Gravity Core Cooling Tank

In an open-pool type research reactor, the primary cooling system can be designed to have a downward flow inside the core during normal operation because of the plate type fuel geometry. There is a flow inversion inside the core from the downward flow by the inertia force of the primary coolant to the upward flow by the natural circulation when the pump is turned off. To delay the flow inversion time, an innovative passive system with pump flywheel and GCCT is developed to remove the residual heat. Before the primary cooling pump starts up, the water level of the GCCT is the same as that of the reactor pool. During the primary cooling pump operation, the water in the GCCT is moved into the reactor pool because of the pump suction head. After the pump stops, the potential head generates a downward flow inside the core by moving the water from the reactor pool to the GCCT and removes the residual heat. When the water levels of the two pools are the same again, the core flow has an inversion of the flow direction, and natural circulation is developed through the flap valves.

Cardiac mucosa at the gastroesophageal junction: An Eastern perspective.

To investigate the nature and origin of cardiac mucosa (CM). Biopsy samples from sixty-one individuals were included in this study. The specimens were taken "at", "just below", or "just above" the gastroesophageal junction, including the histologic squamocolumnar junction. Clinical data were obtained by reviewing electronic medical records for each patient. Patients with a history of stomach adenoma or carcinoma and esophageal carcinoma were excluded, and cases that were endoscopically suspicious of Barrett's esophagus or a polyp were also ruled out. Histologic and endoscopic reviews were performed blinded to the patient's clinical data. Histologic evaluation was conducted by two pathologists, and endoscopic review was performed by a endoscopist with wide experience in the field. Histologically, the columnar epithelium of squamocolumnar junction, presence and severity of acute and chronic inflammation, atrophy, intestinal metaplasia, and presence of carditis were evaluated. Endoscopically, reflux esophagitis was evaluated by Los Angeles (LA) classification, hiatal hernias were classified by Hill grade, and gastroesophageal flap valves were assessed. Fifty-nine of the 61 (96.7%) patients were Korean; 65.6% (40/61) of the patients underwent endoscopy according to the schedule of the National Health Insurance Program as a screening inspection. Of these, only 20.0% (8/40) of cases had reflux symptoms. CM was present in 41/61 (67.2%) individuals, and its presence was associated with older age compared to oxyntocardiac mucosa/oxyntic mucosa (60.59 ± 2.02 years vs 51.55 ± 3.35 years; P = 0.018). The presence of CM was associated with endoscopic diagnosis of esophagitis according to the LA classification (P = 0.022). CM was associated with mononuclear cell infiltration and neutrophilic infiltration, which were statistically significant (P = 0.001, and P = 0.004, respectively). The inflammation of CM, "carditis", showed a statistically significant association with endoscopic diagnosis of reflux esophagitis according to the LA classification (P = 0.008). CM at the gastroesophageal junction is a common histologic finding in biopsy specimens, though not always present, and associated with gastroesophageal reflux disease and carditis severity.

Determination of the Possible Causes of Cracks in Pins of Quick Operating Valves in Hydroelectric Power Plant

During the revision of the individual parts of a hydroelectric power plant the cracks in the pins of quick operating and revision flap valves of Francis turbine were found. Our department has been approached with a request to investigate the causes of these cracks. This paper deals with the complex analysis of influential factors, especially the measurements of residual stresses by hole-drilling method, in order to reveal the factors causing the cracks in the pins.

Research of Double Nozzle Flapper Valve Accelerated Degradation Test

This paper selected the double nozzle flapper type electro-hydraulic servo valve as the research object. Through to analys the wear failure mechanism of electro-hydraulic servo valve to determine the test stress and to select the Pressure gain and leakage as the Degradation performance indicators. So it makes the detail Accelerated degradation test project . and it designs a test system for the pollution wear test. Then, by modeling the degradation process as a drift Brown Motion of which the first passage time follow inverse Gaussian distribution, this paper generated the reliability model of the electro-hydraulic servo valve. Finally, the maximum likelihood combined with least square of accelerated degradation testing data is used to estimate the degradation data of leakage from the test.

Research on Proportional Solenoid Valve Used for Automatic Transmission

The structure of a proportional solenoid valve for automatic transmission is introduced. The design, analysis methodology and dynamic performances of the valve are discussed. Based on the structural analysis of the valve, the operating principle is investigated. Four subsystems that are electric field, magnetic field, mechanical, and hydraulic of the proportional solenoid valve are divided, and their inherent coupling interactions are investigated. The mathematical model of the dynamic performance of the four subsystems is built separately and simulation analysis is carried out. The active process of the proportional solenoid valve is studied by combining with experimental results, verified the correctness of the coupling simulation model. It would be useful for proportional solenoid valve optimal design by analyzing the internal parameters dynamic changes of the valve. In the hydraulic subsystem, the inlet port using ball popper and the nozzle flapper valve for the outlet port. Pressure regulating can be realized by flow control via controlling the opening degree of the outlet. The research results show that the proportional solenoid valve has a small displacement(0.2 mm) in the instantaneous moment of opening, with an open response time less than 2 ms and pressure response time less than 4 ms,it is suitable for automatic transmission control.

Improvement of Performance on Flow-Cutoff of Flap Valves Set in the Pressurized Tank of Pumping Station Based on Numerical Simulation

Two small flap valves arranged in parallel for each pump were used as flow-cutoff device in certain large-scale axial flow pumping station where the pressurized tank was designed as outlet structure. The flap valves of side-set pump had the poorest performance on flow-cutoff in the pumping station. The flow field in the pressurized tank was shown based on numerical simulation in order to improve the flow-cutoff performance of flap valves. The standard k-ε turbulence model and momentum equations were solved in the SIMPLEC algorithm with the assumption that the free water surface remained flat as a stress-free plane of symmetry. The velocity distribution and free outflow were prescribed on inlet and outlet boundary respectively. Numerical simulation on the flow field in pressurized tank was done at three typical moments chosen in the basis of the flow variation in the process of shutdown of flap valves. The reason that two flap valves of side-set pump could not close simultaneously and the late closing flap valve had a huge force on the wall was analyzed based on the comparison of flow field for side-set pump and middle-set pump. The result from numerical simulation proves that the division pier with appropriate size which helps to improve the flow distribution uniformity is valid for the two flap valves of side-set pump to close simultaneously.

A Bayesian approach to unanticipated events frequency estimation in the decision making context of a nuclear research reactor facility

Research reactors are considered as multi-tasking environments having the multiple roles of commercial, research and training facilities. Yet, reactor managers have to make decisions, frequently with high economic impact, based on little available knowledge. A systematic approach employing the Bayes’ theorem is proposed to support the decision making process in a research reactor environment. This approach is characterized by low level complexity, appropriate for research reactor facilities. The methodology is demonstrated through the study of two characteristic events that lead to unanticipated system shutdown, namely the de-energization of the control rod magnet and the flapper valve opening. The results obtained demonstrate the suitability of the Bayesian approach in the decision making context when unanticipated events are considered.

Failure Analysis of a Set of Flapper Valves Under ALT With Alternative Test Device

Abstract In search of further understanding and continuous improvement of mechanical products which suffer dynamics loading, several methods of analysis have been applied, among them, computational simulations and laboratorial experiments. This paper aims to describe the failure mechanics of a regular flapper valve and valve reed used on Hermetic Compressors when tested under accelerated test conditions by a special device, created for testing purpose. The results obtained from the valve reed were plotted on a graph, which reveals the endurance under fatigue, versus the device speed/load change. These curves represent the obtained valve reed lifetime by Weibull ALT (accelerated life test) (statistical analysis). The values obtained were analysed using the normality and the probability approaches beyond t-student. The Weibull ALT graph (fatigue lifetime), microscopic analysis by SEM (scanning electron microscope) and EDS (energy dispersive spectroscopy) were performed on the failed valve reed surface as well as on the valve plate seat utilised throughout the tests.

Augmented Reality Application for the Maintenance of a Flapper Valve of a Fuller-kynion Type M Pump

The overall purpose of this project is to test the impact and potential benefits of Virtual and Augmented Reality technologies (AR&VR) to improve maintenance operation in industrial equipment. The main function for a Flapper valve of a Fuller-Kinyon type M pump is to prevent that the air generated to convey the bulk material through a conveying pipe flows inside of the material chute through the rotating screw. If this will occur, the material flow will decrease or even stop, causing a reduction of the pump capacity. Thus, it is necessary to maintain calibrated each flapper valve in the plant. This process of maintenance is done once a month, or when necessary, and it needs the pump to be shut down, taking up to four hours to finish the complete process. For this reason, an augmented reality application is being developed, aiming to reduce the consumed time by the maintenance process. Using this application, it is expected to dedicate less time training the new personnel responsible for the maintaining process, displaying tridimensional models, animations, images and text information that would simplify the instructions shown in a printed manual and adding an interactive environment between the users and the information displayed. A mobile device either a tablet or a smartphone is to be used as the hardware that will run the application, allowing the user to take it right to the working area, either in a workshop or directly in field. The information displayed includes CAD models of the pump and its components as well as animations illustrating the instructions to follow in each step of the process. Also, the right tool to use in each step will be indicated following by security warnings when needed. This project was developed according to the collaboration cathedra between CEMEX and ITESM, following the LEAD methodology developed by CEMEX to support the project administration, the general process development was constructed from knowledge and experiences gathered among the different previous AR projects developed at ITESM. This information has been studied and “best practices” has been noted, learned and established to develop and implement AR.

The Influence of the Damping Hole Parameters on the Performance of Double Nozzle Flapper Valve Basing on the Orthogonal Test

This paper analyses the flow of the double nozzle flapper valve. Three-dimensional model is established with software Pro/E, fluid analysis software is used for modeling and meshing, CFD method is applied for researching pressure, and flow characteristics of the fixed damping hole is researched when parameters of double nozzle flapper valve is varied. The results show that: the highest velocity through the fixed orifice hole is about 150m/s, the pressure is about 5.9MPa; Using orthogonal test to analyze the simulation results, it is obtained that the power losses of the double nozzle flapper with the change of the diameter, length and the angle of the fixed orifice, the influencing factors on the power losses are the diameter, length and the angle, and the best parameter combination through orthogonal table analysis is gained, which can provide the reference for the whole designing of the double nozzle flapper valve.

2013 EJACULATION PRESERVING TRANS URETHRAL RESECTION OF PROSTATE A PILOT STUDY

You have accessJournal of UrologyBenign Prostatic Hyperplasia: Surgical Therapy and New Technology II1 Apr 20122013 EJACULATION PRESERVING TRANS URETHRAL RESECTION OF PROSTATE A PILOT STUDY Srinath Chandrasekera, Surendra De Zylva, Nilanganie Lamahewage, and Maheesha Kulasinghe Srinath ChandrasekeraSrinath Chandrasekera Nugegoda, Sri Lanka More articles by this author , Surendra De ZylvaSurendra De Zylva Colombo, Sri Lanka More articles by this author , Nilanganie LamahewageNilanganie Lamahewage Colombo, Sri Lanka More articles by this author , and Maheesha KulasingheMaheesha Kulasinghe Nugegoda, Sri Lanka More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.2176AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Despite numerous advances seen in surgery for BPH, retrograde ejaculation remains as the commonest and unconquered morbidity. Given an option most sexually active men undergoing TURP are likely to prefer to have their ejaculation preserved. The objective of this study was to assess the safety and feasibility of our technique of “Ejaculation Preserving TURP” and evaluate short term outcomes. Our study was based on the hypothesis that occluding supra montal prostatic adenoma plays a role in maintaining antegrade ejaculation in men with prostatic obstruction. METHODS We assessed fifteen sexually active males aged 51 to 66 (mean-58.5 years) undergoing Ejaculation Preserving TURP. Mean prostatic volume was 37.6ml (range 12-59ml). Nine were due to failed medical therapy and 6 were in refractory urinary retention. Bipolar TURP was done resecting adenoma at bladder neck including median lobe when present and prostatic urethra. Two small cushions of adenoma and prostatic mucosa were preserved at the prostatic apex and a few millimeters of prostatic urethral mucosa just above the veru montanum. Care was taken not to create “flap valves”. We used a scoring system to assess the degree of projection of the ejaculate “Ejaculation Projection Score”. ie:0=no ejaculation, 1=few drops only, 2=non projectile, 3=projectile, 4=strongly projectile. Patients were assessed pre operatively, at 6 weeks, 3 months, 6 months and 12 months. RESULTS At one year their mean maximum flow rates improved from 6.3ml/S to 22ml/S (p=0.000),residual urine volumes from 120ml to 34ml (p=0.000),IPSS scores from 25 to 5.8 (p=0.000) and quality of life scores from 5.2 to 1.2 (p=0.000). Strikingly, the ejaculatory function remained unchanged (IIEF question 9) from 4 to 3.5 (p=0.02) and “ejaculation projection score” from 3.3 to 3.1 (p=0.57).IIEF score remained unchanged from 54 to 56.4 (p=0.29). 12 /15 had no change or improved ejaculation following surgery and cessation of medical therapy denoting a success rate of 80%.1/15 had complete loss of ejaculation while 2/15 had reduced ejaculation. There were no major morbidities or mortality. CONCLUSIONS Ejaculation Preserving TURP is a safe and feasible option with promising initial results. Our success with various sized adnomata even in those with urinary retention implies the satisfactory degree of unblocking of the outflow with this technique whist preserving antegrade ejaculation. Results of this study further confirms the role of the supra montal prostatic adenoma in maintaining antegrade ejaculation in those with obstructing BPH. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e813 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Srinath Chandrasekera Nugegoda, Sri Lanka More articles by this author Surendra De Zylva Colombo, Sri Lanka More articles by this author Nilanganie Lamahewage Colombo, Sri Lanka More articles by this author Maheesha Kulasinghe Nugegoda, Sri Lanka More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...

Cardiaplication: A Novel Surgical Technique for Refractory Gastroesophageal Reflux in the Pediatric Population

We encountered 3 patients with severe gastroesophageal reflux disease and tubular stomachs precluding fundoplication. Here, we report the use of an innovative technique, cardiaplication, as an alternative approach for antireflux surgery. Three infants with medically refractory gastroesophageal reflux disease (GERD) were referred for fundoplication. In each case, the patient's anatomy prevented a traditional fundoplication from being performed. A cardiaplication was performed by invaginating the cardia of the stomach at the angle of His and securing the invaginated tissue with interrupted silk suture. The plication tubularized the cardia of the stomach, essentially increasing the intra-abdominal portion of the esophagus and altering the angle of His. The imbrication also creates a flapper valve over the distal esophagus, further limiting potential reflux. The charts for the infants who received cardiaplication were reviewed. Radiographic studies and clinical notes for the presence of persistent reflux were evaluated. Cardiaplication was completed in 3 patients with GERD. All cases were initiated laparoscopically and one was converted to an open procedure secondary to dense adhesive disease. Each child was initiated on feeds between postoperative day 2 and 3. Two of the 3 patients were tolerating goal feeds with-in 2 days. The third patient reached goal feeds on day 16. Postoperative imaging (upper gastrointestinal series [UGI]) was obtained in 2 of the 3 patients. At follow-up (13, 7, and 4 months), all 3 patients are clinically free of symptoms of GERD. Delayed radiographic imaging has confirmed that the patients are no longer refluxing. Based on preliminary findings, cardiaplication appears to be a safe and effective surgical technique for the management of severe GERD in infants. We performed cardiaplication out of necessity; however, after further testing this may prove to be an optimal approach, as it can be performed without disruption of the hiatus.

Simulation Research on the Four-Nozzle Flapper Valve Based on GMA

Nozzle-flapper type electro-hydraulic servo valve operated by torque motor has been widely used in industrial applications. As their bandwidths are limited, they are not suitable for high-speed applications. This paper presents a novel nozzle flapper valve driven by the giant magnetostrictive actuator, which has been designed and integrated into the four-nozzle flapper valve to replace the torque motor. And the influence of involved structural parameters on the dynamics of the actuator and the nozzle flapper valve is analyzed by AMESim. The simulation results can provide an important reference and basis for the optimization and design of the four-nozzle flapper valve.

The efferent segment in continent cutaneous urinary diversion: a comprehensive review of the literature

To critically assess the biophysical properties and current status of outlet formation in heterotopic intestinal urinary diversion. As despite three decades of clinical experience with continent cutaneous urinary diversion through bowel segments, no consensus has been reached for the optimal efferent segment although its function largely determines patient satisfaction. A comprehensive Medline literature search using the Medical Subject Headings database (search terms: continent urinary diversion followed by either efferent segment, nipple, Mitrofanoff, Yang-Monti, Benchekroun, tapered ileum, intussuscepted ileum, Kock pouch, T-valve, or Ghonheim) was conducted to identify all full-length original articles addressing the various principles and techniques of outlet formation as well as their outcomes and complications. Examined series were published in English between 1966 and 2010. All studies were systematically evaluated using a checklist (study design, number of patients, etc.) and rated according to the Oxford Centre for Evidence-Based Medicine Levels of Evidence (LoE). While there was a continuous flow of publications over the last three decades, the vast majority of studies were retrospective case series with numerous confounding factors and poorly defined, non-standardized outcomes (LoE, 3). Only a few investigations compare different efferent segments (LoE, 2a). No randomized studies exist. The major biophysical principles are based on the use of flap, nipple, and hydraulic valves. Vermiform appendix, intussuscepted ileal nipple, and the Yang-Monti tube are the most popular techniques and have well-established data on outcomes, complications, and failure rates. Artificial sphincter systems and tissue engineering have provided disappointing results thus far. Most reconstructive strategies are subject to a process of on-going improvement. The continuous quest for optimization has not led to a single universally applicable efferent segment in continent cutaneous urinary diversion. While all techniques have their unique set of advantages and disadvantages, they will always remain a compromise. Success depends on selecting the optimal strategy for individual patients. A major change in principles in the near future is unlikely.

Technology Focus: Completions Today (September 2010)

Technology Focus Making the Good Completion Better The ability of operating and service companies to optimize completion results from standard completion configurations through better reservoir-fluid management has been enhanced greatly by the development of advanced completion hardware [i.e., inflow-control devices (ICDs)]. These devices enable us to “fine tune” flow from individual pay zones that are over- or underpressured. Field performance of wells equipped with ICDs and multisegment-well modeling, including ICDs, have indicated measurable advantages over conventional completion systems. Industry also developed perforating-gun modules that can be configured to perforate the formation in any desired orientation. As each gun module is fired, a flapper valve is actuated to isolate the newly created perforations from the lower, previously stimulated zones. This process ensures accurate and efficient proppant placement. An operator’s goal is to reach production faster, with the widest assortment of specialty tools and hardware, which have been improved continuously over the past decade. Today, many operators use multilaterals, which enable maximum reservoir contact with minimum surface requirements and can accommodate a wide range of completion options. Whether the play is a conventional shallow-gas or deep-gas reservoir or an unconventional-oil/-gas reservoir, use of these technologies can increase production while improving project economics. Reliable and field-proven completion solutions enable creating the ideal conduit from pay zone to surface, regardless of well type or operating environment. This is the key to getting the greatest return on field-development investment and to minimizing life-of-well cost. This overview will not attempt to refer to all new well-completion technologies, but only to highlight a few important recent developments and concepts. Nevertheless, as one searches the literature, the importance of JPT’s role becomes obvious from the large number of references and papers cited with relevance to significant technical achievements in the upstream petroleum industry. There are many papers about technological advances, and I congratulate respective authors in bringing their papers to fruition. Finally, I hope you enjoy reading the selected papers as much as I did during review and selection for the feature. Completions Today additional reading available at OnePetro: www.onepetro.org SPE 125508 • “New Approach to Drilling and Completing Horizontal Wells in Extremely Shallow and Unconsolidated Reservoirs” by Shahryar Saebi, SPE, Schlumberger, et al. SPE 122765 • “World’s First Reverse-Port Uphill Openhole Gravel Pack With Swellable Packers” by Rene Jansen, Brunei Shell Petroleum, et al. SPE 128569 • “Integrated Approach: Perforation-System Optimization for Sand Prevention” by Mohd Zahirin B. Ruslan, SPE, Schlumberger, et al.

Enhancing Well Safety and Economics

Technology Update As the “low-hanging fruit” of the world’s oil and gas accumulations are more fully harvested, so the industry has been forced into tackling more complex and challenging projects such as ultradeep prospects, deepwater applications, and high-pressure/high-temperature (HPHT) wells to continue fulfilling the world’s appetite for fossil energy. This has led to more widespread use of nonconventional techniques such as drilling with casing, coiled-tubing drilling, underbalanced drilling (UBD), and managed-pressure drilling (MPD), including pressurized-mud-cap drilling (PMCD), with their attendant well-control and safety challenges. Among these challenges are Moderate to severe lost circulation Formation damage as a result of having to kill the well before tripping pipe Pore-pressure and fracture-gradient similarity, leading to kick/loss cycles and well-control problems Use of snubbing techniques to trip the pipe in and out of the hole above the “pipe-light” depth, with the associated added cost and risk. Overall operational safety Operational economics As a result, mitigating drilling hazards and reducing operational non-productive time (NPT) has become an extremely important facet of well operations. Downhole-Isolation-Valve System The need to address these challenges led to development of the Downhole Deployment Valve in the year 2000. This is an isolation-valve system consisting of a deep-set flapper valve that is run as an integral part of the intermediate casing string and set at a predetermined depth below the pipe-light depth, or deeper as operational requirements dictate, with a full-opening inside diameter equivalent to that of the casing. It is not a safety valve in the accepted sense of the word, in that it is not a fail-safe device, but rather is powered open and closed by the application of hydraulic pressure at the surface to one of two encapsulated control lines attached to the casing outside diameter (OD). The downhole isolation valve (DIV) can be run in two separate configurations, depending on operational requirements (Fig. 1).